Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already mark this as read-only and open-world, and the description adds substantial behavioral context beyond them. It explains the counting methodology, excludes calls without price data, marks recent calls as pending, and clarifies that only the first call per token/tier/day counts.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded with the tool's purpose and then provides useful methodology and usage notes. It is generally efficient, though the parameter list near the end largely duplicates the schema and could be trimmed.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists, so the description need not explain return formatting. Given the annotations, complete schema coverage, and the description's explanation of aggregation rules and pending behavior, an agent has enough information to call this tool correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so all three parameters are already documented in the input schema. The description restates the allowed values and defaults for period, blockchain, and tier, but does not add meaning beyond what the schema already provides.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a very specific resource: performance statistics for curated CabalSpy calls, grouped per chain and tier. It enumerates the exact metrics returned, including call counts, hit rates for 2x/5x/10x, median peak multiple, time to peak, and best calls, which clearly distinguishes it from a raw calls listing such as get_calls.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives explicit usage examples: "Use this for 'how good are CabalSpy calls' or 'which tier works best'." It does not name alternative sibling tools or state when not to use this tool, so it falls short of a 5, but the intended context is clear.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.